Christopher ris



" UNITED STATES PATENT OFFICE.

CHRISTOPHER RIS, OF BASLE, SWITZERLAND, ASSIGNOR TO JOHN R. GEIGY & 00.,OF SAME PLACE.

BROWN DIAZO DYE AND METHOD OF MAKING SAME.

SPECIFICATION forming part of Letters Patent No. 567,413, datedSeptember 8, 1896. Application filed March 3, 1896. Serial No. 581,652.(Specimena) Patented in France October 2, 1895, No. 250,697.

' To all whom it may concern.-

7 Be it known that I, CHRISTOPHER RIs, a citizen of the SwissConfederation, residing at Basle, in the Republic of Switzerland, haveinvented certain new and useful Improvements in Processes for theProduction of Brown Diazo Dyes, (for which Letters Patent were grantedto me in France, No. 250,697, dated October 2, 1895,) of which thefollowing is a specification.

My invention relates to the production of a new coloring-matterwhichproduces a Very fast and intense brown shade upon unmor- Paradiamin Inthe following I give an example of the production of thecoloring-matter: 18.4 kilos of benzidin are diazotized in the usual manner, then combined with a solution containing fourteen kilos ofsalicylic acid and thirty kilos of carbonate of sodium. The intermediarycompound which is formed is added after some hours to an alkalinesolution of 26.7 kilos of alkylated beta -alpha -amidonaphthol-beta-sulfo-acid, after which the coloring-matter is filtered off and dried.It forms a dark-brown powder, readily soluble in water, with adark-brown color. It dissolves in concentrated sulfuric acid with aviolet-blue color. The aqueous solution is precipitated by acids inclaret-colored flocks and by the action of reducing agents to a slightlybrowncolored solution. 1

Having thus "described my invention, I claim as new and desire to secureby Letters Patent 1. The process herein described of making dantedcotton. This coloring-matter belongs to the class of mixed diazodyestufis and is obtained by the combination of the tetrazo compound ofbenzidin or tolidin or diamidoethoxydiphenyl or diamidodiphenol etherwith two substances, one of which is alkylated beta-alpha,-amidonaphthol-beta -sulfo-acid, while the other is salicylic orcresotinic acid. The products obtained from these homologous substancesare so similar as to be practically identical. 1

The chemical constitution of the new dye is indicated by the followingformula: 1

salicylic (or cresotinic) acid alkylated betaalpha,-amidonaphthol-beta,,-sulfo-acid.

a brown dyestufi, which is obtained by combining the tetrazo compound ofbenzidin with salicylic acid and with alkylated beta -alphaamidonaphthol beta sulfo i acid, substantially as set forth. I

2. The brown coloring-matter herein described, being a dark-brownpowder, readily soluble in water with a dark-brown color, soluble inconcentrated sulfuric acid with a violet-blue color, precipitated byacids in claret-colored flocks and decomposed by reducing agents to aslightly brown-colored solution substantially as set forth. I

In testimony that I claim the foregoing as my invention I have signed myname in presence of the subscribing witnesses.

CHRISTOPHER RIS.

